As the academic atmosphere is getting better and better, various journals dazzle authors. For example, SCI journals, EI journals, core journals and so on, what is the relationship between these three? Next, the editor will share with you briefly about SCI journals, EI journals and core journals.

　　The full name of SCI is science city index, which is a world-famous periodical literature retrieval tool published by the Institute for scientific information (ISI). Its publishing forms include printed periodicals, CD-ROM editions and online databases, as well as web databases on the Internet. SCI includes about 3500 core journals of natural sciences such as mathematics, physics, chemistry, agriculture, forestry, medicine, life science, astronomy, geography, environment, materials, engineering technology, etc. published all over the world.

　　EI is a large-scale comprehensive retrieval tool with the longest history, which was founded by the Federation of American Societies of engineers in 1884. EI enjoys a high reputation in the academic, engineering and information circles around the world, and is an important retrieval tool commonly recognized by the scientific and technological circles.

　　Core periodicals are the main periodicals of a certain subject. Generally, it refers to professional journals with large amount of professional information and high quality, which can represent the development level of professional disciplines and are valued by readers of this discipline. Relevant experts have found that in the actual distribution of document and information sources, there is a core journal effect, that is, a large number of scientific papers in the world of a certain major are concentrated in a small number of scientific journals.

　　It can be seen from the above that there is no relationship between the three. The three systems are completely different. SCI mainly focuses on theoretical research and EI on engineering application. In the fields of biology and medicine, SCI journals have the highest recognition in China, while in the field of engineering technology, EI recognition is relatively high. Compared with Chinese core journals, SCI and EI have higher international recognition.